Radio, the transmission of modulated electromagnetic waves, has been used as a method of communication since the late 19th century. Several different techniques are utilized to modulate radio signals including (but not limited to) modulation techniques that utilize variations in the amplitude, frequency, and/or phase of a radio frequency or RF signal to communicate analog or digital data.
Cellular data networks have been established which enable data to be transmitted and received using mobile devices equipped with an appropriately configured data radio. Several standards exist for cellular data, including General Packet Radio Service (GPRS), Enhanced Data rates for GSM (Global System of Mobile Communications) Evolution (EDGE), High-Speed Downlink Packed Access (HSDPA), Evolved High-speed Packet Access (HSPA+), Evolution-Data Optimized (EVDO), Worldwide Interoperability for Microwave Access (WiMAX), and 3GPP Long Term Evolution (LTE).
Qualcomm Gobi, from Qualcomm, Inc. of San Diego, Calif., is a mobile broadband chipset used to connect to cellular data networks, including GSM HSDPA/HSPA+ cellular data networks and Code Division Multiple Access (CDMA) EVDO rev.A cellular data networks. Gobi mobile broadband chipsets are capable of connecting to both CDMA and GSM cellular data networks using the same piece of silicon, reducing the amount of hardware necessary to support multiple cellular data networks.